Trying to search the OEM weight of 2018 CX9 20inch with 8.5 width. Heard it’s either 30lbs or 39.55lbs. Does anyone knows the weight? Thanks

 

I believe the stock 20" rims are 39.55 lbs. Many 22" rims are closer to 30 so going bigger actually can save some weight!

 

Even if 22s are lighter than 20s, they will still have a higher rotational mass and still hurt acceleration, braking, and handling.

 

Huh? Mass is mass. Many 22" rims have less mass than the 20" rims they are replacing. And many after market tires will help keep the overall mass at each wheel reduced over the stock setup by 5-9 lbs per wheel.

That will improve braking, acceleration and handling.

 

No, apparently you either never took or don't remember your high-school physics class. Here are two quick primmers for you to get back up to speed:

• https://en.wikipedia.org/wiki/Angular_momentum
• https://en.wikipedia.org/wiki/Rotational_energy

 

Assume a tire/wheel weight of 65 lbs per wheel for the stock 20 inch set up with 245/50 tires. Now calculate the energy required to push a tire/wheel weight of 55 lbs per wheel for 22" rims with a 285/35 tires. That is what we are talking about.

 

You're still missing the point, given the fact the weight of the rim portion of the wheel is further from the axis of rotation, it doesn't matter whether the 22" wheel is lighter or not, it will still have a higher rotational mass than the heavier 20" wheel.

 

Do the math. Really, just do the math. You are making several assumptions. First, that the new wheel/tire combo will weigh more on the outside than the inside. Again, that is just an assumption. Second, you are assuming that the total diameter is changing dramatically, which again, is an assumption.

Again do the math. And realize you are using a lighter 22" rim, with almost almost the same wheel/tire weight (lighter), and exact same overall diameter.

 

Overall diameter is not the issue, the issue is the diameter of the rim and the mass of where the metal for the rim is located, you do the math.

 

No point in discussing this further. Although not a complicated issue, you don't seem to understand the concept of a wheel alone and a wheel/tire combo. Diameter is important. Think of a figure skater.

You brought the equations into the discussion to defend your argument. But clearly don't understand them enough to use them to defend your argument.